KR100510831B1 - A Treatment Method For Ammonia Liquor And A Purification Method of COG By Using The Treated Ammonia Liquor - Google Patents

Abstract

This method relates to a method for treating a coke oven gas by using a non-sulphur water treatment method for removing sulfur components from farm water, and a method for purifying coke oven gas using non-sulphur water. Hydrogen emulsification in the farmed water is removed by introducing iron and removing the formed iron sulfide precipitate. The hydrogen sulfide in the coke oven gas is removed with high efficiency by gas-liquid contacting the coarse water and the coke oven gas of 25 degrees C or less processed by emulsification removal. Hydrogen sulfide is reduced, the amount of generation of SO _X by using a COG removed with high efficiency in the fuel and it is possible to manufacture of environmentally friendly clean fuel.

Description

A Treatment Method For Ammonia Liquor And A Purification Method of COG By Using The Treated Ammonia Liquor}

The present invention relates to a coke oven gas purification method using the treated method and the treated non-go. More specifically, the present invention relates to a method for treating a coarse oven gas using a method for treating a non-agricultural water and a method for removing coarse sulfur from a non-sulphur.

Coke Oven Gas (hereinafter referred to simply as 'COG') and water are generated during the coke manufacturing process, and COG contains ammonia and hydrogen sulfide gas to generate SOx and NOx during combustion, thereby polluting the atmosphere. Cause. In addition, the water contains various compounds produced by chemical reactions in the coke distillation. Especially, it contains a large amount of ammonia, which is called ordination. The ordination contains ammonia and sulfur compounds, especially hydrogen sulfide.

On the other hand, since the ordination is used as an absorption neutralizer for removing hydrogen sulfide in the coke oven gas, when the concentration of hydrogen sulfide is high in the ordination used for the hydrogenation scrubber, which is a gas treatment process, the absorption neutralization effect is reduced, thereby reducing COG purification efficiency. In addition, hydrogen sulfide in ordination corrodes process equipment and adversely affects the environment.

Hydrogen emulsion treatment contained in conventional ordination has been performed in ammonia steel, which is a facility for distilling ordination, and in a desorter which desorbs hydrogen and concentrates ammonia. The two complementary facilities that simultaneously realize the above two objectives are combined and operated, and the untreated water prepared in this process is used as a collecting ordination for removing hydrogen sulfide from COG.

However, there is still a large amount of hydrogen emulsified in the (concentrated) ordination generated through this process. Therefore, when it is used as a collecting ordination, the hydrogen sulfide present in the ordination adversely affects the removal of the hydrogen sulfide contained in the COG. That is, the hydrogen sulfide present in the ordination prevents the hydrogen sulfide contained in the COG from dissolving in the ordination, thereby reducing the hydrogen sulfide removal efficiency in the COG.

Accordingly, an object of the present invention is to provide a method for treating a farming and drinking water for removing hydrogen sulfide contained in the farming and drinking water used for COG purification.

Another object of the present invention to provide a COG purification method for removing the hydrogen sulfide in the COG using the concentrated hydrogen water treated with the hydrogen emulsion.

According to one aspect of the invention,

Injecting 5-20% of the equivalent amount of iron sulfate to the amount of hydrogen emulsified water contained in the farm water; And

There is provided a farm water treatment method comprising a; removing the iron sulfide precipitate formed by the reaction of hydrogen sulfide and iron sulfate.

According to another aspect of the present invention,

The coke oven gas purification method which removes hydrogen sulfide in coke oven gas by gas-liquid contacting the coke oven gas and the coke oven gas of 25 degrees C or less processed by the method of the present invention is provided.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

Hydrogen emulsification, an impurity in the surface water used for COG refining, prevents the collection of hydrogen emulsification contained in COG gas. That is, the presence of hydrogen emulsified water in the farmed water decreases the concentration difference with the hydrogen sulfide present in the COG, so that the amount of hydrogen emulsified in the COG that the farmed water can collect is reduced, and thus, the hydrogen removal rate in the COG is lowered.

In the present invention, the sulfur component contained in the hydrogen sulfide is precipitated with insoluble sulfide and removed to remove the hydrogen sulfide contained in the agricultural and hydrophobic water so that the farmed water can effectively collect the hydrogenated hydrogen in the COG. As such, the use of concentrated water with reduced hydrogen sulfide component also increases the hydrogen purification efficiency in COG.

In general, the surface water is hydrogen sulfide desorbed and ammonia is concentrated in the ammonia gas generated from ammonia distillation from the ordination and ammonia steel generated in the coke manufacturing process introduced into the desorate.

The solubility of hydrogen emulsion in water is 258mg / 100g (20 ℃, 1 atm), so hydrogen sulfide is easily dissolved in water. Hydrogen emulsified in this way is dissolved in farmed water as in Scheme 1 and present as hydrogen ions (H ⁺ ) and sulfur ions (S ^-2 ). Therefore, in the present invention, by forming an insoluble precipitate of the sulfur ions to remove the hydrogen sulfide which causes the reduction of the COG purification efficiency during the purification of COG using the farming water.

Preferred metal cations for the removal of sulfur ions as sulfides in the form of insoluble precipitates are iron ions (Fe ⁺⁺ ), cobalt ions (Co ⁺⁺ ), nickel ions (Ni ⁺⁺ ), manganese (Mn ⁺⁺ ), zinc Ions (Zn ⁺⁺ ), iron ions are the most preferable in consideration of the bonding strength with sulfur ions.

They react with sulfur ions (S ^-2 ) equivalently as shown in Equation 3 below, but when cations forming sulfides are present in the same equivalents, they do not exhibit sufficient sulfur ion removal efficiency by side reactions. 5-20% excess, preferably 5-15% excess, more preferably about 10% excess. When the cationic component is added in an excessive amount relative to the sulfur ion component equivalent, hydrogen sulfide in the farmed water is removed by 95% or more.

Hereinafter, the formation of insoluble precipitates of sulfur ions and iron ions will be described in more detail.

Hydrogen emulsion is dissolved in an ionic state in an aqueous solution (20 ° C., 1 atm) as in Scheme 1 below. On the other hand, iron sulfate is dissolved in an aqueous solution and present in an ionic state as in Scheme 2. Therefore, the total dissolution and dissociation reaction of hydrogen sulfide and iron sulfate in the aqueous solution are the same as in Scheme 3. At this time, sulfur ions (S ^-2 ) and iron ions (Fe ⁺² ) react to form an insoluble precipitate of FeS, and by removing the FeS insoluble precipitate, hydrogen sulfide in the farmed water is removed.

The insoluble precipitate can be removed in any way, which is not particularly limited, for example, can be removed by filtration with a filter. In particular, the centrifugal filter can be directly applied to the process, and the sediment can be discharged to the outside, and the concentrated filtrate can be directly circulated in the process.

The hydrogen sulfide in the COG is removed by forming ammonia component and NH ₄ HS in the coarse water by gas-liquid contacting the hydrogen sulfide-treated demineralized water with COG.

In addition, in order to increase the collection efficiency of hydrogen sulfide contained in COG, the temperature of ordination used for hydrogen sulfide capture (hereinafter referred to as 'COG purification') in COG plays an important role. If the temperature of the ordinal water is high, the vapor pressure increases and the collection reaction rate decreases, and thus, the hydrogen sulfide collection efficiency decreases. Therefore, 85% or more of hydrogen sulfide in COG can be collected by managing the temperature of the ordination water used for COG purification at 25 degrees C or less, preferably 25-15 degreeC, more preferably 25 degreeC-room temperature. For example, by installing a heat exchanger during the process, the temperature of the treated ordinal water can be controlled below 25 ° C in the process.

By using the hydrogen sulfide-treated desulfurized water as described above, the purification efficiency of hydrogen sulfide in the COG gas is increased, and the amount of SOx generated is significantly reduced when the hydrogen sulfide is highly removed and purified COG gas is used as the fuel.

Hereinafter, a conventional ordination circulation process for purifying COG and an ordination circulation process according to the present invention will be described in detail.

1 is a process schematic diagram showing a conventional ordination circulation process, and FIG. 2 is a process schematic diagram showing an ordination circulation process according to the present invention.

Conventionally, as shown in FIG. 1, the water is distilled from the ammonia steel (distillation process), and the ammonia gas generated here is desorbed from the hydrogen sulfide in the desorator (concentration process) and the concentration of ammonia is increased. The concentration of ammonia in ordination is 12-14 g / l, but the concentration is increased in the desorter to obtain high concentrations of concentrated snow water at 17-20 g / l.

The farmed water is used to collect hydrogen sulfide contained in the COG gas. The farmed water contains a large amount of hydrogen sulfide at 0.9-1.4 g / l.

Therefore, in the present invention, as shown in FIG. 2, the aqueous solution of iron sulfate is added to a reaction tank for removing hydrogen sulfide in the farmed water and the insoluble iron sulfide formed by the combination of iron and sulfur ions is removed to remove hydrogen sulfide in the farmed water. do.

The resulting iron sulfide particles are removed by centrifugation. Further, in order to improve the collection of hydrogen sulfide in the COG, the treated farmed water is passed through a heat exchanger to control the temperature of the farmed water to 25 ° C or less.

Hereinafter, the present invention will be described in detail through examples.

Example 1

This embodiment shows the hydrogen sulfide removal rate according to the change in the equivalent weight of iron sulfide added to the farming water. Rural water was collected and the chemical components in the Rural water were analyzed and the results are shown in Table 1.

TABLE 1

Chemical composition Free Ammonia Hydrogen sulfide (H ₂ S) Carbon Dioxide (CO ₂ ) Unit (g / l)    17.52   1.32   2.99 Molarity (M)     1.03   0.0388   0.0680

As can be seen from the above table, 10 l of Nong's water present 13.2 g of hydrogen emulsion, which corresponds to 0.388 moles. Accordingly, since 0.388 liter of an aqueous solution of iron sulfate at 1 mol concentration corresponds to the equivalent of hydrogen emulsified water in the farming water, 388 ml of 1 mol iron sulfate was added to the farming water.

In addition, iron sulfate was added to the farming water at 10%, 20%, and 30% of the equivalents to react. The temperature of the surface water was adjusted to 25 ° C.

Thereafter, the iron sulfide precipitate formed in each case was filtered using a centrifugal filter, and the filtrate was collected to analyze the concentration of hydrogen sulfide, and the concentration ratio to the initial value was calculated and the results are shown in FIG. 2.

As can be seen in Figure 2, when the equivalent reaction between hydrogen sulfide and iron sulfide, the hydrogen sulfide removal rate was 93%, which did not reach the proper removal rate of 95%. When iron sulfate was administered in excess of 10% by weight, the hydrogen sulfide removal rate was over 95%.

Example 2

In this embodiment, iron sulfate was used in an excess of 10% of sulfur ions equivalent to remove the hydrogen sulfide gas contained in the COG by gas-liquid contact with the coagulated water and the COG with the hydrogen sulfide removed from the ordination. The collection rate (removal rate) of the hydrogen sulfide gas in COG according to the temperature change of the treated farmed water is shown in FIG. 3. In this embodiment, as the COG, hydrogen sulfide contained 0.03% by volume in COG.

As shown in FIG. 3, the collection rate of the emulsified hydrogen gas contained in the COG of the farming water is different depending on the temperature of the farming water used as the collection liquid.

When the temperature of the farmed water is 30 ℃, the collection rate of hydrogenated hydrogen gas in COG is 73%, which is 85% or less, and when the temperature of the farmed water is 25 ℃ or less, the collection rate is significantly increased to be 85% or more. The hydrogen sulfide gas collection rate is shown.

Example 3

Non-hydrogenated non-hydrogenated nonaqueous water (hydrogen sulfide content 1.32 g / l, using 10% excess equivalents of iron sulfate aqueous solution) and hydrogenated non-hydrogenated nonaqueous water (hydrogen sulfide content 0.01g / l) By collecting the hydrogen sulfide in COG in the same manner as in Example 2 and the results are shown in Table 2.

TABLE 2

Sample Name Untreated untreated water Treatment Hydrogen emulsification rate (%)      81%    87%

The hydrogen sulfide removal rate in COG was better than that in the case of using the sulfur-free treated sulfur-free water of the present invention having a low hydrogen sulfide content.

The hydrogen sulphide in the farmed water is effectively removed, and thus, the hydrogen sulfide is removed and thus the hydrogen sulfide removal rate (capture rate) in the COG is increased by using the farmed water containing a higher concentration of ammonia.

Hydrogen sulfide is reduced, the amount of generation of SO _X by using a COG removed with high efficiency in the fuel and it is possible to manufacture of environmentally friendly clean fuel. In addition, there is an effect to suppress the air pollution, and environmental burden is reduced.

1A is a process schematic diagram showing a conventional ordination treatment process,

Figure 1b is a process schematic showing the ordination treatment process of the present invention,

Figure 2 is a graph showing the hydrogen sulfide removal rate in the fresh water according to the amount of iron sulfate aqueous solution used,

3 is a graph showing the hydrogen sulfide collection rate in the COG according to the farming water temperature.

Claims (4)

Injecting more than 5-20% of the equivalent amount of iron sulfate compared to the equivalent of hydrogen emulsified hydrogen contained in the farming water; And Removing the iron sulfide precipitate formed by the reaction of the hydrogen sulfide and iron sulfate. The method of claim 1, wherein the iron sulfate is added in an amount of 5-15% over the equivalent of hydrogen sulfide. The coke oven gas purification method which removes hydrogen sulfide in coke oven gas by gas-liquid contacting the coarse water below 25 degreeC processed by the method of Claim 1, and coke oven gas. 4. The method according to claim 3, wherein the concentration of the surface water is 25 to 15 ° C.